Mom may have taught you that sharing is good, but we know that snooping is even better. Case in point: It's nice to share your iTunes library with your peers over the network at school or work - but it's even better to eavesdrop on those peers and find out what kind of music they're listening to when they think nobody's paying attention.

Step 1: The Setup

If your Mac isn't set up to share your iTunes playlists, start here. If you're already sharing, go to step 2. Open up iTunes > Preferences, and click Sharing. Check the Share My Music box, and decide whether you want to share your whole iTunes library or only specific playlists, then type a name for your shared stuff. (This appears in other users' iTunes Source lists). Leave the password blank to make people feel welcome - and to maximize your chances of busting them grooving to Barry Manilow.

Share and share alike.

Step 2: The Snooper

Download iTunes Monitor (free, www.ebyss.net/pages/software.html). Drag the app into your Mac's Applications folder, and double-click to launch it. The iTunes Monitor window displays a list of connected users and any files in your Music folder that are in use - but it doesn't dig into nested subfolders. If you're not scared of a little Unix action, you can dig deeper.